US 6,205,566 B1 · Semiconductor integrated circuit, method for designing the same, and storage medium where design program for semiconductor integrated circuit is stored

Abstract

In a semiconductor integrated circuit, a select signal output circuit switches a selector to take in the output of a circuit section in response to a signal “0” received at the D terminal thereof during normal operation. Thus, a scan flip-flop receives the output of the circuit section. During a scan test mode, a select signal “0” or “1” is input through a scan-in terminal to the select signal output circuit and then to the selector. If the select signal is “0”, then the selector selects the output of the circuit section. On the other hand, if the select signal is “1”, then the selector selects a clock signal supplied from a clock signal generator. The output of the circuit section or the clock signal supplied from the clock signal generator, which has been input to the scan flip-flop, is passed through a scan path and output to the outside through a scan-out terminal. As a result, an internally formed clock signal generator or the like can be tested easily.

Claims28

Dependent claims

A semiconductor integrated circuit comprising:

a storage device including a data input terminal and a control terminal and constituting a part of a scan path;
a first circuit section for generating data to be supplied to the data input terminal of the storage device during normal operation;
and
a second circuit section for generating a signal to be supplied to the control terminal of the storage device during the normal operation;
wherein the semiconductor integrated circuit further comprises:
a selector for selecting one of an output signal of the first circuit section and an output signal of the second circuit section and supplying the selected signal to the data input terminal of the storage device;
and
a select signal output circuit for outputting a select signal to the selector, the select signal instructing a select operation of the selector,
and wherein the select signal output circuit outputs the select signal instructing that the selector selects the output signal of the first circuit section during the normal operation and outputs the select signal instructing that the selector selects an arbitrary one of the output signal of the first circuit section and the output signal of the second circuit section during testing the semiconductor integrated circuit.

6 more elements

A semiconductor integrated circuit comprising:

a first storage device including a control terminal and constituting a part of a scan path;
a second storage device including a data input terminal and constituting another part of the scan path;
a first circuit section for generating data to be supplied to the data input terminal of the second storage device during normal operation;
and
a second circuit section for generating a signal to be supplied to the control terminal of the first storage device during the normal operation;
wherein the semiconductor integrated circuit further comprises:
a selector for selecting one of an output signal of the first circuit section and an output signal of the second circuit section and supplying the selected signal to the data input terminal of the second storage device;
and
a select signal output circuit for outputting a select signal to the selector, the select signal instructing a select operation of the selector,
and wherein the select signal output circuit outputs the select signal instructing that the selector selects the output signal of the first circuit section during the normal operation and outputs the select signal instructing that the selector selects an arbitrary one of the output signal of the first circuit section and the output signal of the second circuit section during testing the semiconductor integrated circuit.

7 more elements

A method for designing a semiconductor integrated circuit for testing the operation of an internal circuit,

the method comprising the steps of:
inputting a net list of a semiconductor integrated circuit including:
a first storage device including a control terminal;
a second storage device including a data input terminal;
a first circuit section for generating data to be supplied to the data input terminal of the second storage device;
and a second circuit section for generating a signal to be supplied to the control terminal of the first storage device;
adding a selector and a select signal output circuit to the semiconductor integrated circuit, the selector selecting one of an output signal of the first circuit section and an output signal of the second circuit section and supplying the selected signal to the data input terminal of the second storage device, the select signal output circuit outputting a select signal, instructing a select operation of the selector, to the selector;
and
constituting the first and second storage devices by scan flip-flops, respectively, and inserting a scan path, including the scan flip-flops, into the semiconductor integrated circuit.

6 more elements

A storage medium in which a design program for designing a semiconductor integrated circuit testing the operation of an internal circuit is stored,

the design program comprising the steps of:
inputting a net list of a semiconductor integrated circuit including:
a first storage device including a control terminal;
a second storage device including a data input terminal;
a first circuit section for generating data to be supplied to the data input terminal of the second storage device;
and a second circuit section for generating a signal to be supplied to the control terminal of the first storage device;
adding a selector and a select signal output circuit to the semiconductor integrated circuit, the selector selecting one of an output signal of the first circuit section and an output signal of the second circuit section and supplying the selected signal to the data input terminal of the second storage device, the select signal output circuit outputting a select signal, instructing a select operation of the selector, to the selector;
and
constituting the first and second storage devices by scan flip-flops, respectively, and inserting a scan path, including the scan flip-flops, into the semiconductor integrated circuit.

6 more elements

Dependencies are inferred from the claim text.

Semiconductor integrated circuit, method for designing the same, and storage medium where design program for semiconductor integrated circuit is stored

Life of this patent

Semiconductor integrated circuit, method for designing the same, and storage medium where design program for semiconductor integrated circuit is stored

Life of this patent

Abstract

Claims28